The archbishop of New York, Cardinal Timothy Dolan, explains the "mixed emotions" he feels about the news that Pope Benedict XVI will resign.

Updated at 4:01 p.m. ET: Pope Benedict XVI’s abdication announcement at a small event at the Vatican on Monday came as such a surprise that even the cardinals in the room were astonished — a sentiment echoed around the world as church leaders and laity alike grappled with the news.

"All the cardinals remained shocked and were looking at each other," Monsignor Oscar Sanchez of Mexico, who was in the room at the time of the announcement, said, according to The Associated Press.

The pope said Monday that he no longer had the strength to carry out his ministry and would step aside Feb. 28 as leader of the world’s 1.2 billion Catholics. Speaking in Latin, Benedict, 85, announced his decision during an address at a small gathering of cardinals.

"I’m as startled as the rest of you and as anxious to find out exactly what’s going on," Cardinal Timothy Dolan, the archbishop of New York, said on TODAY. "Except for prayer, I don’t know what else to do. I’ll await instruction with everyone else."

Like other prominent figures in the church, Dolan said that it was a somber occasion and that the decision only deepened his respect for the pope.

Dolan, who was appointed to his post in 2009 and elevated to cardinal early last year by Benedict himself, is considered a longshot candidate to succeed the pope. He said that he found himself “kind of somber” upon hearing of the resignation.

"Boy, I love this pope," the cardinal said. "The world looks to him with respect and affection."

Vatican spokesman Greg Burke discusses Pope Benedict XVI's decision to step down, saying it did not come as a complete surprise to Vatican officials, who have known for "at least several weeks."

President Barack Obama said in a statement: “Michelle and I warmly remember our meeting with the Holy Father in 2009, and I have appreciated our work together over these last four years.”

Benedict becomes the first pope to abdicate since the Middle Ages. When he made the announcement, several cardinals in the room did not even understand what was happening, a Vatican spokesman said.

Archbishop Vincent Nichols, leader of the Archdiocese of Westminster, which includes parts of London, said the pope’s announcement “has shocked and surprised everyone.”

“Yet, on reflection, I am sure that many will recognize it to be a decision of great courage and characteristic clarity of mind and action,” Nichols, who is also president of the Catholic Bishops’ Conference of England and Wales, said in a statement.

He said Catholics would remember Benedict’s papacy “with great affection and the highest esteem for his minister as our Holy Father.”

The spiritual head of the world’s 80 million Anglicans, Justin Welby, the archbishop of Canterbury, said that he learned of the news “with a heavy heart but complete understanding.”

“We pray that God will bless him profoundly in retirement with health and peace of mind and heart, and we entrust to the Holy Spirit those who have a responsibility to elect his successor,” he said in a statement, according to Reuters.

At St. Patrick’s Cathedral, in Manhattan, Dave Stacker said that he supported the pope’s decision but wondered how it might affect the church. He said that he admired the pope’s embrace of social media — Benedict late last year posted from a Twitter account, @pontifex.

Catholics United, an interest group that wants the church to focus more on social justice and poverty than on abortion and homosexuality, praised Benedict for his humility but said the departure was a chance to reflect on “the challenges of this papacy.”

“To many, the Catholic church hierarchy has been seen as an institution overly focused on issues of human sexuality, such as opposition to access to birth control and marriage equality, rather than first serving the poor as Christ commanded,” said James Salt, the group’s executive director.

House Speaker John Boehner, a Catholic, said that “extraordinary humility and love for the church” had been hallmarks of Benedict’s service and were reflected in his decision.

“Americans were inspired by his visit to the United States in 2008, and by his quiet, steady leadership of the church in uncertain times,” he said in a statement.

The archbishop of Washington, Cardinal Donald Wuerl, told reporters at St. Matthew’s Cathedral that he had been working on a homily at 5 a.m. when he received a call and learned of Benedict’s abdication.

He said that the move was an “enormous surprise” but also sounded a note of continuity for the church.

“Transitions in the church are not new,” he said. “With each passing pontificate, the church turns to filling the See of Peter. And this has gone on for 2,000 years, so this will not be a new experience.”